The invention concerns a drum for carding machines, the casing of said drum being made of steel sheet, each end of which is supported by a hub attached to the drive shaft.
Drums and rollers used to feed fiber material into textile machines, and to process and transform fiber material in said machines, are made of different materials. There are card drums, for example, and draw-off rollers, clearers and carding work drums that are made of cast iron or steel. Each of these materials has disadvantages. Cast iron drums are very heavy and, aside from a high expenditure of force for repair or maintenance work to be performed on them, they require more driving power. It is a known fact that card drums made of steel are considerably lighter, and that the disadvantages listed above, therefore, apply to a much lesser extent to drums made of steel.
Nevertheless, steel drums have not been practical so far. One of the main reasons for this is the lack of dimensional stability in the static and dynamic states, especially when carding at the high drum speeds used today, and with drums of greater widths. Card drums, consisting of a casing supported at its ends by means of cross spokes on the shaft, have been provided with reinforcing, annular ribs, distributed over the length of the casing. This has resulted in satisfactory dimensional stability with cast iron drums. This design has not, however, proved itself satisfactory with steel drums.